EL PASO – The bare-bones steel pipe and metal roof structure overlooking the Rio Grande resembles a worn-out bus stop. But to the Border Patrol agents who use it, it's become a monument to the rising tide of violence aimed their way.

The number of times rifle fire has struck the shelter's bullet-proof glass can be counted in the nine star-shaped patterns that spread out like a spider's web. Several smaller, neater scars mark the spots where rocks and chunks of concrete were heaved at Border Patrol agents.

A bulletproof glass pane offers scant protection for senior Border Patrol agent Ramiro Cordero near El Paso. Just a few yards away, an agent's windshield was shot out. And on Jan. 13, another agent trying to stop an illegal entry was hit near the left eye by a large rock thrown with stunning accuracy from the Mexican bank. It took 25 stitches to repair the wound.

Violent assaults on agents are up 108 percent along the southwest border, national Border Patrol Chief David Aguilar said Thursday.